The present invention relates to a train wheel of an electronic timepiece having more than two rotors and two hand wheels, and more particularly to a supporting structure of hand wheels which are driven by the rotors independently of each other.
In the case of an electronic timepiece having two rotors wherein the drive forces from the rotors are transmitted to the hand wheels through individual train wheels, it has been known as shown in FIG. 2, to provide the second train wheel for driving the second hand wheel 14 with the second rotor 15 through the second drive transmitting wheel 16 and the first train wheel for driving the first hand wheel 13 with the first rotor 17 through the first drive transmitting wheel 18. The second hand wheel 14 has a pipe 14a defining a rotational axis and the first hand wheel 13a has a shaft 13a as defining a rotational axis. The shaft 13a of the first hand wheel 13 is inserted in the axis pipe 14a of the second hand wheel 14 so as to be slidably guided by the inner surface of the pipe 14a.
In the case of the above structure, when the first hand wheel 13 is driven to rotate by the first rotor 17, a problem arises that the second hand wheel 14 tends, though slightly, to be rotationally driven resulting in swinging the hand attached to the second hand wheel 14 since the rotational shaft 13a of the first hand wheel comes into direct contact with the rotational pipe 14a of the first hand wheel.